Electrical connections, particularly those which intermittently carry relatively high currents, are susceptible to failure as a result of corrosion in which a layer of non-conductive material (for example, an oxide layer) develops at the point of connection to render an apparently secure connection electrically marginal or unusable. A highly prevalent and notorious example is the pair of detachable connections to the battery in automotive vehicles and the like. Such connections typically take the form of a screw (or otherwise) tightenable assembly at the end of a battery cable which is introduced over a lead battery terminal and simply tightened to afford frictional engagement. The presence of corrosive fumes, high operating temperatures, intermittent high current demand (as when starting), and other harsh operating conditions result in a condition of apparent battery failure which can only be genuinely remedied by removing the cable, cleaning both the connector assembly and the battery terminal and reconnecting the cable.
Various attempts in the past have been made to counteract this ubiquitous problem. One common procedure is to coat the assembled connection with a layer of grease, the object being to "seal" the connection to thereby prevent the corrosive fumes from accessing the interface between the connector assembly and the battery terminal to thereby inhibit the chemical reaction which produces the layer of non-conductive material. Although this procedure is helpful, at least temporarily, in slowing down the formation of the non-conductive layer, the "seal" is either never fully effected (the bottom of the connector often being inaccessible to applying the grease layer) or it fails as the grease is subjected to the aforementioned underhood conditions. Another approach, sometimes employed particularly with automotive battery connections, is to place a material proximate the battery connection (for example, a ring of the material introduced over the battery terminal before the connector assembly) which serves to chemically inhibit the effect of the corrosive fumes at the interface between the battery terminal and the connector assembly. Experience has shown that this approach is of limited effectiveness over a lifetime which is also limited.
Therefore, those skilled in the electrical art will appreciate that it would be highly desirable to provide means by which electrical connections of long term reliability may be obtained, especially those connections made in harsh environments such as experienced at the battery terminals under the hood in an automotive vehicle.